Warning Signs

What causes potentially deadly rhabdomyolysis in endurance athletes?

Photo by Chris Hunter

Squaw Valley, California, hosts the Western States 100-Mile Endurance Run (WS100), a grueling foot race that packs a punch for even the most elite athletes. In 2009, five of the 400 participants were hospitalized with nausea, mental changes, low blood-sodium levels and rhabdomyolysis (extreme muscle damage) including the first signs of kidney failure.

The same year another report documented that four athletes participating in the 95-mile West Highland Way Race in Scotland were overcome with low blood-sodium levels and kidney problems relating to rhabdomyolysis.

In January of 2011, a dozen University of Iowa football players were hospitalized with exercise-induced (or exertional) rhabdomyolysis, after an intense group workout that included 100 squats in addition to other high-intensity, full-body exercises. Recently, rhabdomyolysis cases have even been connected to participation in popular “muscle-confusion” workout programs, such as P90X, CrossFit and the Insanity Workout.